X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/f7cf5898d8f5ec774640e3e0888ec627ce4692be..48ffc52cc96fc0665183d9a9e3f68e7e031487f4:/NEWS diff --git a/NEWS b/NEWS index c1589a145..348c2f650 100644 --- a/NEWS +++ b/NEWS @@ -1,10 +1,701 @@ Guile NEWS --- history of user-visible changes. -Copyright (C) 1996-2012 Free Software Foundation, Inc. +Copyright (C) 1996-2013 Free Software Foundation, Inc. See the end for copying conditions. Please send Guile bug reports to bug-guile@gnu.org. +Changes in 2.0.8 (since 2.0.7): + +* TODO + +Reorder points in order of importance and make comprehensible + +Assemble thanks + +* Notable changes + +** New guile.m4. + +The `guile.m4' autoconf macros have been rewritten to use `guild' and +`pkg-config' instead of the deprecated `guile-config' (which itself +calls pkg-config). + +There is also a new macro, `GUILE_PKG', which allows packages to select +the version of Guile that they want to compile against. See "Autoconf +Macros" in the manual, for more information. + +** Better Windows support. + +Guile now correctly identifies absolute paths on Windows (MinGW), and +creates files on that platform according to its path conventions. See +XXX in the manual, for all details. + +In addition, the new Gnulib imports provide `select' and `poll' on +Windows builds. + +As an incompatible change, systems that are missing were +previously provided a public `scm_std_select' C function that defined a +version of `select', but unhappily it also provided its own incompatible +definitions for FD_SET, FD_ZERO, and other system interface. Guile +should not be setting these macros in public API, so this interface was +removed on those plaforms (basically only MinGW). + +** Gnulib update. + +Guile's copy of Gnulib was updated to v0.0-7865-ga828bb2. The following +modules were imported from Gnulib: select, times, pipe-posix, fstat, +getlogin, and poll. + +** New optimizations. + +There were a number of improvements to the partial evaluator, allowing +complete reduction of forms such as: + + ((let ((_ 10)) (lambda () _))) + + ((lambda _ _)) + + (apply (lambda _ _) 1 2 3 '(4)) + + (call-with-values (lambda () (values 1 2)) (lambda _ _)) + +A number (ahem) of numeric operations on have been made faster, among +them GCD and logarithms. + +Finally, `array-ref', `array-set!' on arrays of rank 1 or 2 is now +faster, because it avoids building a rest list. Similarly, the +one-argument case of `array-for-each' and `array-map!' has been +optimized, and `array-copy!' and `array-fill!' are faster. + +** `include' resolves relative file names relative to including file. + +Given a relative file name, `include' will look for it relative to the +directory of the including file. This harmonizes the behavior of +`include' with that of `load'. + +** SLIB compatibility restored. + +Guile 2.0.8 is now compatible with SLIB. You will have to use a +development version of SLIB, however, until a new version of SLIB is +released. + +** Better ,trace REPL command. + +Sometimes the ,trace output for nested function calls could overflow the +terminal width, which wasn't useful. Now there is a limit to the amount +of space the prefix will take. See the documentation for ",trace" for +more information. + +** Update predefined character sets to Unicode 6.2. + +** GMP 4.2 or later required + +Guile used to require GMP at least version 4.1 (released in May 2002), +and now requires at least version 4.2 (released in March 2006). + +* Manual updates + +** Better SXML documentation. + +The documentation for SXML modules was much improved, though there is +still far to go. See "SXML" in manual. + +** Style updates. + +Use of "iff" was replaced with standard English. Keyword arguments are +now documented consistently, along with their default values. + +** An end to the generated-documentation experiment. + +When Guile 2.0 imported some modules from Guile-Lib, they came with a +system that generated documentation from docstrings and module +commentaries. This produced terrible documentation. We finally bit the +bullet and incorporated these modules into the main text, and will be +improving them manually over time, as is the case with SXML. Help is +appreciated. + +** New documentation. + +There is now documentation for `scm_array_type', and `scm_array_ref', as +well as for the new `array-length' / 'scm_c_array_length' / +`scm_array_length' functions. `array-in-bounds?' has better +documentation as well. The `program-arguments-alist' and +`program-lambda-list' functions are now documented. Finally, the GOOPS +class hierarchy diagram has been regenerated for the web and print +output formats. + +* New deprecations + +** Deprecate generalized vector interface. + +The generalized vector interface, introduced in 1.8.0, is simply a +redundant, verbose interface to arrays of rank 1. `array-ref' and +similar functions are entirely sufficient. Thus, +`scm_generalized_vector_p', `scm_generalized_vector_length', +`scm_generalized_vector_ref', `scm_generalized_vector_set_x', and +`scm_generalized_vector_to_list' are now deprecated. + +** Deprecate SCM_CHAR_CODE_LIMIT and char-code-limit. + +These constants were defined to 256, which is not the highest codepoint +supported by Guile. Given that they were useless and incorrect, they +have been deprecated. + +** Deprecate `http-get*'. + +The new `#:streaming?' argument to `http-get' subsumes the functionality +of `http-get*' (introduced in 2.0.7). Also, the `#:extra-headers' +argument is deprecated in favor of `#:headers'. + +** Deprecate (ice-9 mapping). + +This module, present in Guile since 1996 but never used or documented, +has never worked in Guile 2.0. It has now been deprecated and will be +removed in Guile 2.2. + +** Deprecate undocumented array-related C functions. + +These are `scm_array_fill_int', `scm_ra_eqp', `scm_ra_lessp', +`scm_ra_leqp', `scm_ra_grp', `scm_ra_greqp', `scm_ra_sum', +`scm_ra_product', `scm_ra_difference', `scm_ra_divide', and +`scm_array_identity'. + + +* New interfaces + +** `round-ash', a bit-shifting operator that rounds on right-shift. + +See "Bitwise Operations". + +** New environment variables: `GUILE_STACK_SIZE', `GUILE_INSTALL_LOCALE'. + +See "Environment Variables". + +** New procedure `sendfile'. + +See "File System". + +** New procedures for dealing with file names. + +See "File System" for documentation on `system-file-name-convention', +`file-name-separator?', `absolute-file-name?', and +`file-name-separator-string'. + +** Escape continuations with `call/ec' and `let/ec' + +See "Prompt Primitives". + +** `array-length', an array's first dimension. + +See "Array Procedures". + +** `hash-count', for hash tables. + +See "Hash Tables". + +** New foreign types: `ssize_t', `ptrdiff_t'. + +See "Foreign Types". + +** New C helpers: `scm_from_ptrdiff_t', `scm_to_ptrdiff_t'. + +See "Integers". + +** Much more capable `xml->sxml' + +See "Reading and Writing XML" for information on how the `xml->sxml' +parser deals with namespaces, processed entities, doctypes, and literal +strings. Incidentally, `current-ssax-error-port' is now a parameter +object. + +** New command-line argument: `--language'. + +See "Command-line Options" in the manual. + +** `current-language' in default environment. + +Previously defined only in `(system base language)', `current-language' +is now defined in the default environment, and is used to determine the +language for the REPL, and for `compile-and-load'. + +** New procedure: `fluid->parameter' + +See "Parameters", for information on how to convert a fluid to a +parameter. + +** New procedures to read all characters from a port + +See "Line/Delimited" in the manual for documentation on `read-string' + and `read-string!'. + +** New HTTP client procedures. + +See "Web Client" for documentation on the new `http-head', `http-post', +`http-put', `http-delete', `http-trace', and `http-options' procedures, +and also for more options to `http-get'. + +** New procedures for converting strings to and from bytevectors. + +See "Representing Strings as Bytes" for documention on the new `(ice-9 +iconv)' module and its `bytevector->string' and `string->bytevector' +procedures. + +** New `print' REPL option. + +See "REPL Commands" in the manual for information on the new +user-customizable REPL printer. + +** New variable: %site-ccache-dir. + +The "Installing Site Packages" and "Build Config" manual sections now +refer to this variable to describe where users should install their +`.go' files. + +* Build fixes + +** Fix compilation against libgc 7.3. +** Fix cross-compilation of `c-tokenize.o'. +** Fix warning when compiling against glibc 2.17. +** Fix documentation build against Texinfo 5.0. +** Fix building Guile from a directory with non-ASCII characters. +** Fix native MinGW build. +** Fix --disable-posix build. +** Fix MinGW builds with networking, POSIX, and thread support. + +* Bug fixes + +** SRFI-37: Fix infinite loop when parsing optional-argument short options + (http://bugs.gnu.org/13176) +** web: Support non-GMT date headers in the HTTP client + (http://bugs.gnu.org/13544) +** Avoid stack overflows with `par-map' and nested futures in general + (http://bugs.gnu.org/13188) +** A fork when multiple threads are running will now print a warning. +** Allow for spurious wakeups from pthread_cond_wait. + (http://bugs.gnu.org/10641) +** Warn and ignore module autoload failures. + (http://bugs.gnu.org/12202) +** Use chmod portably in (system base compile). + (http://bugs.gnu.org/10474) +** Fix response-body-port for HTTP responses without content-length. + (http://bugs.gnu.org/13857) +** Allow case-lambda expressions with no clauses. + (http://bugs.gnu.org/9776) +** Improve standards conformance of string->number. + (http://bugs.gnu.org/11887) +** Support calls and tail-calls with more than 255 formals. +** ,option evaluates its right-hand-side. + (http://bugs.gnu.org/13076) +** Structs with tail arrays are not simple. + (http://bugs.gnu.org/12808) +** Make `SCM_LONG_BIT' usable in preprocessor conditionals. + (http://bugs.gnu.org/13848) +** Fix thread-unsafe lazy initializations. +** Allow SMOB mark procedures to be called from parallel markers. + (http://bugs.gnu.org/13611) +** Fix later-bindings-win logic in with-fluids. + (http://bugs.gnu.org/13843) +** Fix duplicate removal of with-fluids. + (http://bugs.gnu.org/13838) +** Support calling foreign functions of 10 arguments or more. + (http://bugs.gnu.org/13809) +** Let reverse! accept arbitrary types as second argument. + (http://bugs.gnu.org/13835) +** Recognize the `x86_64.*-gnux32' triplet. +** Check whether a triplet's OS part specifies an ABI. +** Recognize mips64* as having 32-bit pointers by default. +** Remove language/glil/decompile-assembly.scm. + (http://bugs.gnu.org/10622) +** Use O_BINARY in `copy-file', `load-objcode', `mkstemp'. +** Fix compilation of functions with more than 255 local variables. +** Fix `getgroups' for when zero supplementary group IDs exist. +** Allow (define-macro name (lambda ...)). +** Various fixes to the (texinfo) modules. +** guild: Gracefully handle failures to install the locale. +** Fix format string warnings for ~!, ~|, ~/, ~q, ~Q, and ~^. + (http://bugs.gnu.org/13485) +** Fix source annotation bug in psyntax 'expand-body'. +** Ecmascript: Fix conversion to boolean for non-numbers. +** A failure to find a module's file does not prevent future loading. +** Many (oop goops save) fixes. +** `http-get': don't shutdown write end of socket. + (http://bugs.gnu.org/13095) +** Avoid signed integer overflow in scm_product. +** http: read-response-body always returns bytevector or #f, never EOF. +** web: Correctly detect "No route to host" conditions. +** `system*': failure to execvp no longer leaks dangling processes + (http://bugs.gnu.org/13166) +** More sensible case-lambda* dispatch + (http://bugs.gnu.org/12929) +** Do not defer expansion of internal define-syntax forms. + (http://bugs.gnu.org/13509) + + + +Changes in 2.0.7 (since 2.0.6): + +* Notable changes + +** SRFI-105 curly infix expressions are supported + +Curly infix expressions as described at +http://srfi.schemers.org/srfi-105/srfi-105.html are now supported by +Guile's reader. This allows users to write things like {a * {b + c}} +instead of (* a (+ b c)). SRFI-105 support is enabled by using the +`#!curly-infix' directive in source code, or the `curly-infix' reader +option. See the manual for details. + +** Reader options may now be per-port + +Historically, `read-options' and related procedures would manipulate +global options, affecting the `read' procedure for all threads, and all +current uses of `read'. + +Guile can now associate `read' options with specific ports, allowing +different ports to use different options. For instance, the +`#!fold-case' and `#!no-fold-case' reader directives have been +implemented, and their effect is to modify the current read options of +the current port only; similarly for `#!curly-infix'. Thus, it is +possible, for instance, to have one port reading case-sensitive code, +while another port reads case-insensitive code. + +** Futures may now be nested + +Futures may now be nested: a future can itself spawn and then `touch' +other futures. In addition, any thread that touches a future that has +not completed now processes other futures while waiting for the touched +future to completed. This allows all threads to be kept busy, and was +made possible by the use of delimited continuations (see the manual for +details.) + +Consequently, `par-map' and `par-for-each' have been rewritten and can +now use all cores. + +** `GUILE_LOAD_PATH' et al can now add directories to the end of the path + +`GUILE_LOAD_PATH' and `GUILE_LOAD_COMPILED_PATH' can now be used to add +directories to both ends of the load path. If the special path +component `...' (ellipsis) is present in these environment variables, +then the default path is put in place of the ellipsis, otherwise the +default path is placed at the end. See "Environment Variables" in the +manual for details. + +** `load-in-vicinity' search for `.go' files in `%load-compiled-path' + +Previously, `load-in-vicinity' would look for compiled files in the +auto-compilation cache, but not in `%load-compiled-path'. This is now +fixed. This affects `load', and the `-l' command-line flag. See + for details. + +** Extension search order fixed, and LD_LIBRARY_PATH preserved + +Up to 2.0.6, Guile would modify the `LD_LIBRARY_PATH' environment +variable (or whichever is relevant for the host OS) to insert its own +default extension directories in the search path (using GNU libltdl +facilities was not possible here.) This approach was problematic in two +ways. + +First, the `LD_LIBRARY_PATH' modification would be visible to +sub-processes, and would also affect future calls to `dlopen', which +could lead to subtle bugs in the application or sub-processes. Second, +when the installation prefix is /usr, the `LD_LIBRARY_PATH' modification +would typically end up inserting /usr/lib before /usr/local/lib in the +search path, which is often the opposite of system-wide settings such as +`ld.so.conf'. + +Both issues have now been fixed. + +** `make-vtable-vtable' is now deprecated + +Programs should instead use `make-vtable' and `'. + +** The `-Wduplicate-case-datum' and `-Wbad-case-datum' are enabled + +These recently introduced warnings have been documented and are now +enabled by default when auto-compiling. + +** Optimize calls to `equal?' or `eqv?' with a constant argument + +The compiler simplifies calls to `equal?' or `eqv?' with a constant +argument to use `eq?' instead, when applicable. + +* Manual updates + +** SRFI-9 records now documented under "Compound Data Types" + +The documentation of SRFI-9 record types has been moved in the "Compound +Data Types", next to Guile's other record APIs. A new section +introduces the various record APIs, and describes the trade-offs they +make. These changes were made in an attempt to better guide users +through the maze of records API, and to recommend SRFI-9 as the main +API. + +The documentation of Guile's raw `struct' API has also been improved. + +** (ice-9 and-let-star) and (ice-9 curried-definitions) now documented + +These modules were missing from the manual. + +* New interfaces + +** New "functional record setters" as a GNU extension of SRFI-9 + +The (srfi srfi-9 gnu) module now provides three new macros to deal with +"updates" of immutable records: `define-immutable-record-type', +`set-field', and `set-fields'. + +The first one allows record type "functional setters" to be defined; +such setters keep the record unchanged, and instead return a new record +with only one different field. The remaining macros provide the same +functionality, and also optimize updates of multiple or nested fields. +See the manual for details. + +** web: New `http-get*', `response-body-port', and `text-content-type?' + procedures + +These procedures return a port from which to read the response's body. +Unlike `http-get' and `read-response-body', they allow the body to be +processed incrementally instead of being stored entirely in memory. + +The `text-content-type?' predicate allows users to determine whether the +content type of a response is textual. + +See the manual for details. + +** `string-split' accepts character sets and predicates + +The `string-split' procedure can now be given a SRFI-14 character set or +a predicate, instead of just a character. + +** R6RS SRFI support + +Previously, in R6RS modules, Guile incorrectly ignored components of +SRFI module names after the SRFI number, making it impossible to specify +sub-libraries. This release corrects this, bringing us into accordance +with SRFI 97. + +** `define-public' is no a longer curried definition by default + +The (ice-9 curried-definitions) should be used for such uses. See the +manual for details. + +* Build fixes + +** Remove reference to `scm_init_popen' when `fork' is unavailable + +This fixes a MinGW build issue (http://bugs.gnu.org/12477). + +** Fix race between installing `guild' and the `guile-tools' symlink + +* Bug fixes + +** Procedures returned by `eval' now have docstrings + (http://bugs.gnu.org/12173) +** web client: correctly handle uri-query, etc. in relative URI headers + (http://bugs.gnu.org/12827) +** Fix docs for R6RS `hashtable-copy' +** R6RS `string-for-each' now accepts multiple string arguments +** Fix out-of-range error in the compiler's CSE pass + (http://bugs.gnu.org/12883) +** Add missing R6RS `open-file-input/output-port' procedure +** Futures: Avoid creating the worker pool more than once +** Fix invalid assertion about mutex ownership in threads.c + (http://bugs.gnu.org/12719) +** Have `SCM_NUM2FLOAT' and `SCM_NUM2DOUBLE' use `scm_to_double' +** The `scandir' procedure now uses `lstat' instead of `stat' +** Fix `generalized-vector->list' indexing bug with shared arrays + (http://bugs.gnu.org/12465) +** web: Change `http-get' to try all the addresses for the given URI +** Implement `hash' for structs + (http://lists.gnu.org/archive/html/guile-devel/2012-10/msg00031.html) +** `read' now adds source properties for data types beyond pairs +** Improve error reporting in `append!' +** In fold-matches, set regexp/notbol unless matching string start +** Don't stat(2) and access(2) the .go location before using it +** SRFI-19: use zero padding for hours in ISO 8601 format, not blanks +** web: Fix uri-encoding for strings with no unreserved chars, and octets 0-15 +** More robust texinfo alias handling +** Optimize `format' and `simple-format' + (http://bugs.gnu.org/12033) +** Angle of -0.0 is pi, not zero + + +Changes in 2.0.6 (since 2.0.5): + +* Notable changes + +** New optimization pass: common subexpression elimination (CSE) + +Guile's optimizer will now run a CSE pass after partial evaluation. +This pass propagates static information about branches taken, bound +lexicals, and effects from an expression's dominators. It can replace +common subexpressions with their boolean values (potentially enabling +dead code elimination), equivalent bound lexicals, or it can elide them +entirely, depending on the context in which they are executed. This +pass is especially useful in removing duplicate type checks, such as +those produced by SRFI-9 record accessors. + +** Improvements to the partial evaluator + +Peval can now hoist tests that are common to both branches of a +conditional into the test. This can help with long chains of +conditionals, such as those generated by the `match' macro. Peval can +now do simple beta-reductions of procedures with rest arguments. It +also avoids residualizing degenerate lexical aliases, even when full +inlining is not possible. Finally, peval now uses the effects analysis +introduced for the CSE pass. More precise effects analysis allows peval +to move more code. + +** Run finalizers asynchronously in asyncs + +Finalizers are now run asynchronously, via an async. See Asyncs in the +manual. This allows Guile and user code to safely allocate memory while +holding a mutex. + +** Update SRFI-14 character sets to Unicode 6.1 + +Note that this update causes the Latin-1 characters `§' and `¶' to be +reclassified as punctuation. They were previously considered to be part +of `char-set:symbol'. + +** Better source information for datums + +When the `positions' reader option is on, as it is by default, Guile's +reader will record source information for more kinds of datums. + +** Improved error and warning messages + +`syntax-violation' errors now prefer `subform' for source info, with +`form' as fallback. Syntactic errors in `cond' and `case' now produce +better errors. `case' can now warn on duplicate datums, or datums that +cannot be usefully compared with `eqv?'. `-Warity-mismatch' now handles +applicable structs. `-Wformat' is more robust in the presence of +`gettext'. Finally, various exceptions thrown by the Web modules now +define appropriate exception printers. + +** A few important bug fixes in the HTTP modules. + +Guile's web server framework now checks if an application returns a body +where it is not permitted, for example in response to a HEAD request, +and warn or truncate the response as appropriate. Bad requests now +cause a 400 Bad Request response to be printed before closing the port. +Finally, some date-printing and URL-parsing bugs were fixed. + +** Pretty-print improvements + +When Guile needs to pretty-print Tree-IL, it will try to reconstruct +`cond', `or`, and other derived syntax forms from the primitive tree-IL +forms. It also uses the original names instead of the fresh unique +names, when it is unambiguous to do so. This can be seen in the output +of REPL commands like `,optimize'. + +Also, the `pretty-print' procedure has a new keyword argument, +`#:max-expr-width'. + +** Fix memory leak involving applicable SMOBs + +At some point in the 1.9.x series, Guile began leaking any applicable +SMOB that was actually applied. (There was a weak-key map from SMOB to +trampoline functions, where the value had a strong reference on the +key.) This has been fixed. There was much rejoicing! + +** Support for HTTP/1.1 chunked transfer coding + +See "Transfer Codings" in the manual, for more. + +** Micro-optimizations + +A pile of micro-optimizations: the `string-trim' function when called +with `char-set:whitespace'; the `(web http)' parsers; SMOB application; +conversion of raw UTF-8 and UTF-32 data to and from SCM strings; vlists +and vhashes; `read' when processing string literals. + +** Incompatible change to `scandir' + +As was the original intention, `scandir' now runs the `select?' +procedure on all items, including subdirectories and the `.' and `..' +entries. It receives the basename of the file in question instead of +the full name. We apologize for this incompatible change to this +function introduced in the 2.0.4 release. + +* Manual updates + +The manual has been made much more consistent in its naming conventions +with regards to formal parameters of functions. Thanks to Bake Timmons. + +* New interfaces + +** New C function: `scm_to_pointer' +** New C inline functions: `scm_new_smob', `scm_new_double_smob' +** (ice-9 format): Add ~h specifier for localized number output. +** (web response): New procedure: `response-must-not-include-body?' +** New predicate: 'supports-source-properties?' +** New C helpers: `scm_c_values', `scm_c_nvalues' +** Newly public inline C function: `scm_unget_byte' +** (language tree-il): New functions: `tree-il=?', `tree-il-hash' +** New fluid: `%default-port-conversion-strategy' +** New syntax: `=>' within `case' +** (web http): `make-chunked-input-port', `make-chunked-output-port' +** (web http): `declare-opaque-header!' + +Search the manual for these identifiers, for more information. + +* New deprecations + +** `close-io-port' deprecated + +Use `close-port'. + +** `scm_sym2var' deprecated + +In most cases, replace with `scm_lookup' or `scm_module_variable'. Use +`scm_define' or `scm_module_ensure_local_variable' if the second +argument is nonzero. See "Accessing Modules from C" in the manual, for +full details. + +** Lookup closures deprecated + +These were never documented. See "Module System Reflection" in the +manual for replacements. + +* Build fixes + +** Fix compilation against uninstalled Guile on non-GNU platforms. +** Fix `SCM_I_ERROR' definition for MinGW without networking. +** Fix compilation with the Sun C compiler. +** Fix check for `clock_gettime' on OpenBSD and some other systems. +** Fix build with --enable-debug-malloc. +** Honor $(program_transform_name) for the `guile-tools' symlink. +** Fix cross-compilation of GOOPS-using code. + +* Bug fixes + +** Fix use of unitialized stat buffer in search-path of absolute paths. +** Avoid calling `freelocale' with a NULL argument. +** Work around erroneous tr_TR locale in Darwin 8 in tests. +** Fix `getaddrinfo' test for Darwin 8. +** Use Gnulib's `regex' module for better regex portability. +** `source-properties' and friends work on any object +** Rewrite open-process in C, for robustness related to threads and fork +** Fix vector-length when applied to other uniform vector types +** Fix escape-only prompt optimization (was disabled previously) +** Fix a segfault when /dev/urandom is not accessible +** Fix flush on soft ports, so that it actually runs. +** Better compatibility of SRFI-9 records with core records +** Fix and clarify documentation of `sorted?'. +** Fix IEEE-754 endianness conversion in bytevectors. +** Correct thunk check in the `wind' instruction. +** Add @acronym support to texinfo modules +** Fix docbook->texi for without URL +** Fix `setvbuf' to leave the line/column number unchanged. +** Add missing public declaration for `scm_take_from_input_buffers'. +** Fix relative file name canonicalization with empty %LOAD-PATH entries. +** Import newer (ice-9 match) from Chibi-Scheme. +** Fix unbound variables and unbound values in ECMAScript runtime. +** Make SRFI-6 string ports Unicode-capable. + + Changes in 2.0.5 (since 2.0.4): This release fixes the binary interface information (SONAME) of